Human genetics are determined by the chromosomes passed down from the person's parents. Every child gets 23 chromosomes from each parent, and the trait is determined by whether or not the dominant or the recessive trait is adopted. You can predict what trait a child will have by using family pedigrees and punnett squares. Each of these are explained in the Inheritance section of the review. Scientists use a method called karyotyping to view chromosomes. However, karyotyping is often used to determine sex-linked traits. The karyotype below shows that, based on the two X chromosomes, the person is a female. A lot of sex-linked traits occur because of the difference between having one X-chromosome, and 2. Having 2 X-chromosomes gives females extra, or backup copies of that specific DNA, in case anything were to go wrong in the first one.
-punnett squares can accurately reflect the genotypes of the two parents offspring.
(here is an example of a punnett square....)
sex linked genes
-color vision genes are located on the 'x' chromosome
-men have only one 'x' chromosome so therefore men only need one recessive trait to have colorblindness
-Watson and crick were two genetic scientists who collectivly discovered the 'double helix' structure of DNA
this is how colorblindness seems to some people...
-a gene specifically is a sequence od DNA. This sequence gives information that will be used to make proteins, these proteins define the traits.
-an allele is a for of a gene.
-When a gene is homozygous, it has two of the same forms of the gene's traits (either both recessive or both dominant.)
-When a gene is heterozygous, it has two different forms of the gene's traits (one recessive and one dominant)
-The geneotype is the makeup of an organism's DNA. The geneotype is determined by the multiple alleles that define an organism's traits
-punnett squares can accurately reflect the genotypes of the two parents offspring.
(here is an example of a punnett square....)
sex linked genes
-color vision genes are located on the 'x' chromosome
-men have only one 'x' chromosome so therefore men only need one recessive trait to have colorblindness
-Watson and crick were two genetic scientists who collectivly discovered the 'double helix' structure of DNA
this is how colorblindness seems to some people...
-a gene specifically is a sequence od DNA. This sequence gives information that will be used to make proteins, these proteins define the traits.
-an allele is a for of a gene.
-When a gene is homozygous, it has two of the same forms of the gene's traits (either both recessive or both dominant.)
-When a gene is heterozygous, it has two different forms of the gene's traits (one recessive and one dominant)
-The geneotype is the makeup of an organism's DNA. The geneotype is determined by the multiple alleles that define an organism's traits
For more info please visit http://www.youtube.com/watch?v=oIyG5kByokQ
Mutations
Deletion mutation- a mutation where one or more of the base pairs gets deleted from the strand of DNA.
(example from the link below...)
Point mutation- when a nitrogenous base gets switched with another nitrogenous base.
(example from the link below...)
Frame-Shift- a mutation when one segment gets moved to another part of the DNA sequence.
(example from the link below...)
Inversion mutations- when a whole segment of the DNA gets flipped backwards or inverts.
(example from the link below...)
Insertion Mutations-when DNA that is unnecessary to the DNA sequence gets added to the strand of DNA.
(example from the link below...)
Here is are two helpful links that further expands on these types of mutations...
http://www.genetichealth.com/g101_changes_in_dna.shtml
http://evolution.berkeley.edu/evolibrary/article/mutations_03